
No. 427.] HAIRS OF LEPIDOPTEROUS LARVA. 567 
attention of Bethe ('96), whoinvestigated this point and found two 
sorts of hairs in Astacus, one as described by Retzius, in which 
the cavity of the hair was shut off at its base by chitin, and the 
other having its cavity freely open at the base. In the closed 
hair a nerve fiber was seen to stop at the base of the hair, but 
in the open hair it was continued a short distance into the 
shaft, and he suggests that probably this fiber goes nearer 
the tip than was observed in the specimens. 
It was only by means of sections that it was possible to 
trace the nerve in the cavity of the hair, and I found it very 


Fic. 6. — The figure in the cen i th t the left views of subhypodermal nerves 
= us tror the "silkworm the bie ? th n are also shown. The figures at the 
y ) Methylen blue. 

difficult to obtain successful preparations. In the silkworm 
nerves were traced to the hairs by means of sections, which 
showed the nerves passing between the hypodermal cells, past 
the gland cell, or trichogen cell, without any branches, and often 
as far as the collar of the hair. In a few cases the nerves were 
traced a short distance into the shaft; but they appeared to 
end not far from the base of the hair on the side of the lumen 
(Fig. 7). Either in the hair or just below it a rather large 
